Support for spherical pressure vessels



Nov. 28, 1944. L. REisER 2,363,992

SUPPORT FOR SPHERICAL PRESSURE VESSELS Filed May 9, 1942 Lea Raiser INVENTOR.

Ara-6min:

Patented New. 2.3%4

than SUPEGRT FOR SPHERNJAEI PRIESSE WES SEILE Leo Raiser, Milwaukee, Wis, ssslgnor-to A. 0.

Smith Corporation, Milwaukee. Win, a corporation of New York This invention relates to a support for spherical pressure vessels and the like.

It has been applied in the supporting of pres- 7 sure vessels wherein the internal fluid pressure is a major factor involved inthe maintaining of the shape of the vessel and where the weight of the fluid contents is a lesser. factor in determining the shape of the vessel.

The principal object of the invention is to utilize an available excess strength of the vessel wall to provide a-natural membrane support for the vessel.

Another object isto provide a'less costly. support for a spherical type pressure vessel, and one which requires less metal for the weight of vessel and contents involved.

' Other objects and advantages will appear hereinafter. I n

An embodiment of the invention is illustrated in the accompanying drawing in which:

Figure 1 is a vertical central section through a vessel and its support;

Fig. 2 is an'enlarged view. of the supporting ring and membrane in similar section;

Fig. 31s a horizontal section through the support looking upwardly at line 3-4 of Fig. 1; and

Fig. 4 is a stress or force diagram illustrating the components of force involved in the supporting membrane.

y In accordance with the invention the sphertwenty-seven feet in diameter and may be designed to withstand about one hundred pounds per-square inch internal pressure with a factor of safety of three based upon the ultimate tensile strength of the steel and considering the welded joints as having an efliciency of approximately eighty percent of that of the plate stock, a requirement of the past codes. The working pressure is generally, suflicient to cause the vessel to retain its substantially spherical shape quite regardlessvof its support so long as the latter uniformly distributes the weight of.

the vessel and its contents over a substantial area of contact with the support.

The support of the present invention utilizes the bottom of the vessel as a membrane by tying it to a conical membrane ring substantially tangent thereto at the weld joining the two. The membrane ring I hangs from the supporting ring 4 and the structure functions as though a membrane sheet were stretched" tightly over the supporting ring 4 and the vessel supported thereon.

The invention utilizes the wall of the vessel within the circle of weld I as the membrane and I sheet by reason of the required computation of ical pressure vessel l is supported by a con :al

membrane ring 2 welded at its inner edge by fillet weld I to the outer surface of the lower part of-the vessel. The membrane ring 2 is welded at its outer edge to a rigid supporting ring 4 resting on a-suitable-foundation 5.

In the embodiment illustrated, and by way of example; the. vessel I maybe constructed of steel spectlve adjacent plates I along vertical lines by welds III. The bottom plate 8 is Joined to the lower ends of the loweraseries of plates -8 by the circular weld II and the top plate I is simiklarly Joined to the upper ends of the upper series of plates 1 by the circular weld l2.

The vessel thus constructed may be about the welds in the vessel at eighty percent of the strength of the plates. r In the specific construction example here previously referred to the ring 2 may be about a footwide and three-quarters of an inch thick. This thickness of the ring 2 enables the fillet weld 3 to be large andto spread over a substantial area of the surface of the vessel to thereby avoid undesirable stress concentrations.

The supporting ring 4 to which the membrane ing the lowerflange of the beam support. An

upper thick plate. I8 is welded to the upper edge of web I4 and constitutes the upper flange of the beam. The weld II secures the :ring 2 to the inner edge of upper plate l6. Vertical ribs I! are preferably provided on the outer side of the supporting ring 4 to strengthen and add rigidity tothe upper and lower flangeathe ribs II being welded to the lower plate l5, vertical web and upper plate II.

The upper plate It constitutes a compression ring which holds the membrane tight and prevents undue sagging of the vessel wall in the sagging of the wall occur.

. central bottom area within the circle or weld s.

weight and to lie against the conical ring 2. The

construction of the ring 2 tangent to the vessel wall at the jcinder 3 provides fora supporting of the vessel wall by .the ring should any slight The location and diameter of. ring 2 relative to the vessel wall should be such as to utilize as. much or the available strength of the vessel wa for the membrane as possible and still stay within an economic construction. In general, for most practical purposes it will be satisfactory-to locate the ring I with its weld 3 below the 45.

angle on'the lower quadrant of the vessel.

This location of the contact point or line between ring 2 and the vessel may be more simply expressed in terms of theangle ofthe conical ring 2 with the vertical at the point of contact. This is illustrated in Fig. 4 which gives a general force diagram for a given location.

In Fig. 4 the weight of the vessel and its contents is represented by line W which for'convenience is drawn vertical at the line of contact and is in terms of total weight divided by the length in inches of the circular line of contact between the inner edge of ring 2 and the vessel wall. 'The line .1" is disposed tangential to the wall of -the sphere and represents thetorce or pull -per inch of circumference in the conical ring 2 at the point of contact with the vessel wall as a ccmponentin the direction between weld 3 and weld IS. The component force F may be determined by drawing a horizontal line C at right angles .to W from the upper end'of the line W to the line F. C represents the radial com-t ponent of force per inch of length acting on ring I and setting up compressional stresses therein.

' The tangent line F should be at an acute angle A to the vertical line W, preferably not less than 45". As the conical membrane ring 2 is enlarged in. diameter its angle A to the perpendicularwill progressively change to a smallerangle, in order to maintain the tangential rela-' tionship of the ring to the vessel wall. As the ring 2 is made smaller the angle A becomes larger until it reaches a right angle when the ring is at the center of the bottom.-

The best position of .the ring 2 will depend upon the thickness. and rigidity of the vessel wall and the weight of the vessel and its contents.- For most practical purposes, a position in which the-angle A v is between about 45 and about 70 is preferable; 1 I

The invention may be applied to otheitypes of vessels with. horizontal circular contours such as an ellipsoid" of revolution about a vertical axis.

In'suchacasetheweight of the liquid is usually 1 a-iarger facto'r 'as related to the internal pres-' sure-.ithamsis the case with a spherical vessel.-

Where the'b'ottom of such a vessel is more nearly i'iat, the'suppontihgmembrane ring will be placed 1 nearer the -outer circumI-erence of the vessel with bangle of tllfl'lng similar to thatfor spheri cal-vessels.

1;.Where the-:we'ight 'thecent er'is of primary importance and .the radial support of theside tanksfit is 1 possible .toutilize a discontinuous membrane structure in ..the form or radial straps.

aseaoss the vessel horizontally, ,and a tension member.

secured at its outer edge to said ring and at its inner edge to the vessel wall, said'tension mem-- ber lying substantially tangential to the vessel wall and in contact therewith along a circular horizontal line substantially below the horizontal equator of the vessel.

2. A support for a vessel of the class described,

comprising a rigid compression ring encircling the vessel horizontally, and a tension member secured at its outer edge to said ring and at its inner edge to the vessel wall, said tension mem-' ber lying substantially tangential to the vessel wall and in contact therewith along a circular horizontal line substantially below the horizontal equator of the vessel, said member makin an acuate angi'e between about 45 and about -with the vertical axis of the vessel.

3. A support for a substantially spherical pressure vessel comprising a rigili corpression ring encircling the vessel horizontally, and a conical membrane-like ring welded at its. outer upper edge to the compression ring and at its-inner lower edge to the vessel wall, the vessel lying within the hollow of the membrane-like ring with the ring disposed substantially tangential to the vessel wall at the circular line of contact therebetween.

4. A support for a substantially spherical pres!- sure vessel comprising a rigid compression ring encircling the vessel horizontally, and a conical membrane-like supporting ring welded at its outer upper edge to the compression ring and at its inner lower edge to the vessel wall, theves- 'sel lying within the hollow of the membranelike supporting ring with the membrane supporting ring disposed substantially tangential to the vessel wall at the circular-line of contact there-' between, said membrane-like supporting ring. making an acute angle between about 45 and about 70 with the vertical axis of the cone thereof. a i

5. A support fora vessel of the class described,

in which the vessel has a single head plate atits outer circumference to apply tension forces to said head plate and thereby provide with said head plate a membrane-like support for the vessel. c

6. A support for a-vessel of the class described, comprising a metal ring disposed substantially tangential to the vessel wall ata horizontal circular I line, and secured thereto to .utilize; aportionoi the vessel wall. as 'part of a supporting membrane. and a rigid horizontal supporting ring secured to said first named ring to suspend-the 1 same and the ,vessel therein.

7. Asupport for-a vessel of. the class described,

comprising a. metal ring disposed substantially r tangential to the vessel wall at a horizontal eonsof less importance,. as in liquidstorage circular line, "and secured thereto to utilize a portion of thevessel wall as a supportin brane, a'rigid horizontally disposed supporting ring'i'or saidring, and a compression plate on the upper end of said supporting ring extending away irom said vessel and spaced therefrom to hold the tangentially disposed ring tight and prevent undue sagging of the vessel wall in the central bottom area of the same.

8.1!. support for a vessel of the class described, comprising a metal ring disposed substantially tangential to the vessel wall at a horizontal circular line, and secured thereto to utilize a portion of the vessel wall as a supporting membrane, a rigid horizontally disposed supporting ring for suspending said tangentially disposed ring, a compression plate on the upper end 01 said supporting ring extending away from said vessel and spaced therefrom to hold the tangentially disposed ring tight and prevent undue sagof the same, and means to additionally secure-said plate to the lower portion of the supporting ring to add rigidity to the ring and prevent any substantial contact'oi said plate with the wall 01 the vessel.

9. A support for a substantially spherical pressure vessel comprising a rigid compression ring encircling the vessel horizontally, and a conical ring welded at its outer edgeto the compressionring and at its inner lower edge to the vessel wall and tangentially disposed relative to the latter, the portion of the vessel wall lying within the tangentially disposed ring constituting therewith a membranedlke support for said vessel;

LEO REIBER.

3v ging oi the vessel wall in the central bottom area 

